Effects on adolescents' lipid profile of a fitness-enhancing intervention in the school setting; the EDUFIT study.

OBJECTIVES Observational studies have reported an association among physical activity, fitness and lipid profile in youth. The purpose of this study was to analyse the effect of a school-based intervention focused on increasing the number and intensity of Physical Education (PE) sessions a week, on adolescents' lipid profile. METHODS A 4-month group-randomized controlled trial was conducted in 67 adolescents (12-14 years-old) from South-East Spain, 2007. Three school classes were randomly allocated into control group (CG), experimental group-1 (EG1) and experimental group-2 (EG2). The CG received the usual PE in Spain (2 sessions/week), the EG1 received 4 PE sessions/week, and the EG2 received 4 PE sessions/week of high intensity. The main study outcomes were fasting levels of total cholesterol, high-density lipoprotein cholesterol (HDLc), low-density lipoprotein cholesterol (LDLc) and triglycerides. All the analyses were adjusted for sex, sexual maturation, attendance and baseline value of the outcome studied. RESULTS The intervention did not positively affect cardio-metabolic parameters except for LDLc, that was marginally yet significantly reduced in EG2 (-10.4 mg/dl), compared with the CG (+4.1 mg/dl) (p = 0.04); no differences were observed however for the LDLc/HDLc ratio. No significant effects were observed in EG1. DISCUSSION Overall, a 4-month school-based physical activity intervention did not substantially influence lipid profile in adolescents. However, the results suggest that increasing both frequency and intensity of PE sessions had a modest effect on LDLc in youth. Future studies involving larger sample sizes and longer interventions should focus on the separate effects of volume and intensity of PE.